Selecting and actuating mechanism for crossbar switches



June 23, 1953 J. l. BELLAMY 2,643,299

SELECTING AND ACTUATING MECHANISM FOR CROSSBAR SWITCHES Original Filed MaIich l, 1944 r 44h" INVENTOR JOHN I. BELLAMY ATTORNEY Patented .Iune 23, 1953 SELECTING AND ACTUATING MECHANISM FOR CROSSBAR SWITCHES John I. Bellamy, Wheaton, Ill., assignor, by mesne assignments, to Kellogg Switchboard and Supply Company, a. corporationof Delaware Original application March 1, 1944, Serial No.

524,816, now Patent No. 2,490g665', dated December 6, 1949. Divided and this application April 19, 1949', Serial No. 88,274

6 Claims.

This invention relates to selecting. and actuating mechanism for a crossbar switch. The main object of the invention is to provide new and improved selecting and actuating mechanism for the stackups of contact members of a crossbar switch which is more reliable in operation and is more economical to manufacture.

This application constitutes a division of my prior application, Serial No. 524,816, filed March 1, 1944, now Patent Nor 2,490,665, issued Decemher 6, 1949.

A. crossbar switch as disclosed in the abovenoted prior application includes a succession of similar individual switch assemblies, each comprising a cross row of selectively operable stackups of contact members, and common selecting shafts arranged to selectastackup of contacts of anysuch assembly.

Features of the invention: covered; in this application relate to a simplified select-finger'construction and a simplified arrangement for mounting and controlling the several selecting fingers of an individual switch assembly of the crossbar switch. Each such simplified select'finger comprises a pivoted hairpin-like loop of spring material of which the front portion serves as a selecting and actuating portion; an intermediate portion cooperates with the pivot; and the rear portion serves as flexible arms through which the associated selecting shaft positions the finger.

Other objects and features of the invention, largely subordinate to the foregoing, will appear hereinafter.

The accompanying drawings, comprising Figs.

1 to 4, show a preferred embodiment of the invention:

Fig. 1 is a top View of one individual switch assembly in mounted position, with certain parts broken away;

Fig. 2 is a front view of the switch assembly of selection control by the illustrated select shafts 43 which extend in front of all the individual switch assemblies of thecomplete crossbar switch. The select shafts 43 are pivotally mounted at their ends and are individually controlled to rotate a few degrees in either desired direction from normal position as fully disclosed in the previously identified parent application.

A contact bank may comprise parts held in assembled condition by three screws H39, and is secured to frame by two bolts I32. Contact bank 60 has similar stackups of contacts I to It! extending therefrom, of which the tenth stackup is shown in side view in Fig. 3. This stackup includes three contact pairs, each of which includes. a relatively rigid. overlying member ItI and a relatively flexible underlying member H5 permanently paired therewith and arranged to contact the overlying member when the assembly of insulating studs 9I is raised through the medium of depending actuating. tab I26 on the underlying actuating. spring I21.

The flexible members H8 in any level of the several stackups. I to I0 are preferably electrically connected together as. by being. formed as individual flexible teeth of. a comb-like structure whose back portion is clamped within contact bank 60 andis. provided with a rearwardly ex tending terminal portion H3, as fully disclosed the noted parent application.

The relativel rigid contactmembers IOI have respective rear terminal portions I 01 which have the illustrated side lugsv through which vertically extending wires may be attached to interconnect these contact members with respectively corresponding ones in the stackups of the other individual switch assemblies in the manner common to crossbar switch construction. Member I'0I of any stackup has openings H39 therethrough accommodating the alignment of control-studs 9| which operate freely therethrough.

Frame 65 includesan upwardly offset-portion 82 which supports. the free end of actuating blades I to I, which in turn support the respective alignments of control studs EH.

Actuation of a desired stackup is accomplished by the common actuating plate 69 which underlies the actuating tabs. I28 within a cutout portion of frame 65. Plate 69 is provided at. its ends witha-ngularly disposed portions having suitable openings through. which it is suspended on lugs 14 and I5 extending forward from frame 65. The assembly is. retained pivotally in place on these lugs by angularly disposed end portions of. retaining. spring. 76, secured to frame 65 by screws 11.

The actuating plate 69 is of magnetic mateamazed on the frame 65 which underlies stop lug fi l carried by plate 59. Preferably plate 69 is stiffened as by a downward embossing operation, creating a longitudinal channel iii.

Stackups l to iii comprise five pairs of adjacent stackups, and each such pair is provided with a select finger 81, a separate one for each of the select shafts 33. The select fingers are pivotally related to actuating plate 6?; through respective pivots 91 which may be formed on the actuating plate by raising cylindrical portions by a semi-perforating operation. Plate-like retaining strip 92 may be assembled with actuating plate 69 as by spot welding it to the upper end of each of the pivots 9i.

Each select finger 8'5 may be constructed of a single piece of round wire, for example, formed into the illustrated modified hairpin shape. The portion at the forward end, where the two arms or shanks are joined, is the selecting portion. This portion is comparatively wid in the illustrated embodiment to give the finger more stability against a tendency to warp in installed position, as well as to conform to the comparatively wide separation between stackups. The generally rectangular configuration of the finger 8?, followed .by the illustrated nearly semicircular pivot-engaging portion in each sidearm, provides corner portions just underneath retaining strip 92 which serves to limit tilting of the finger. The two side arms of any select finger are preferably inwardly tensioned sufficiently to provide a light gripping action at its pivot 9| which is useful in limiting return overthrow and in damping vibrational action of the finger incident to its operation or its release from operated position.

Arms as of any finger 8'! extend rearwardly from the vicinity of its pivot 9i to lie on opposite sides of the front portion of web M formed with the associated shaft $3. The rotational location of the finger is thereby placed under control of the select shaft. Each such select shaft normally stands in its illustrated normal position, and is capable of rotation by alternative electromagnets a few degrees in either direction from normal position, according to which one of the two associated stackups of an individual switch assembly is to be selected. Such rotation carries the free end of any associated finger 8i beneath the depending tab 523 of the concerned stackup. If electromagnet I42 is then energized to raise actuating plate G9, the concerned forward side portion of the operated select finger Bl then bridges the underlying opening 85 in plate 69 to raise the overlying actuating tab I28. The selected stackup is thereby actuated through the resulting raising of its column of studs i it. Each flexible member H8 in the stackup is thereby brought into firm electrical engagement with its overlying contact member IUI.

At any stackup where a select finger has not been placed underneath its actuating tab i28 when armature 69 is raised, no contact is made with the concerned actuating tab I28. Such tab thus freely enters the underlying window 85 in actuating plate 69.

Finger stops 86 are provided on actuating plate 69 for th respective fingers 8?. stops may be provided by a shear-forming operation which raises them a suitable distance above the surrounding upper face of part 69. Any such stop terminates the movement of its finger 8'! toward select position at the desired point in its travel, when it has reached a location coinciding substantially with the center line of the overlying actuating blade I2! and studs H9. Additional movement of the rotating select shaft #33 is permitted by an outward flexing of the concerned arm 90 to insure that each finger controlled thereby has reached its desired select position.

Ordinarily, when a stackup has been actuated as above set forth, the electromagnet I42 is maintained energized for some time to hold armature 69 and the stackup in operated position. During this time, the forward end of the concerned finger 81 is trapped comparatively firmly between plate 69 and the slightly sloped lower face of the concerned actuating tab H8. The off-normal select shaft 33 is ordinarily returned to its illustrated normal position as soon as the selecting operation is followed by the desired stackup closure. When thi occurs the opposite rear arm 90 of the trapped select finger 8'! is moved outwardly until the entire shank of the finger moves out of contact with pivot 91. Because of the comparatively great length of flexible material then involved, the necessary flexing can occur without requiring more than a small return force to be exerted on the select shaft. If the same select shaft is then moved in the opposite direction to select the paired stackup in another individual switch assembly, the trapped select finger 81 is flexed an additional amount to permit the movement.

When the connection through the actuating stackup is no longer desired, deenergization of electromagnet Hi2 releases the associated armature 63 to permit the actuating plate 69 to fall by gravity toits illustrated normal position, permitting the contact elements in the previously closed stackup to return to their illustrated normal open condition, and releasing the trapped finger 8?. Such finger thereupon springs back into the position corresponding to the rotational position currently occupied by its associated select shaft 43.

An additional function of the flexibility of finger 8! arises when plate 69 has been actuated to close a stackup thereof associated with a given select shaft, following which another select shaft is rotated to select a stackup of another individual switch assembly. When this occurs the forward side of the rotating finger B1 of the lastmentioned shaft cannot pass underneath its associated actuating tab I28, which is then extending into the underlying opening 85. Consequently the movement of forward end of the finger is blocked at a point very near the normal position thereof. The entire remaining travel of the control web 54 of the concerned shaft 43 is readily permitted by the flexing of the driven rear arm 99 of the blocked finger away from the trailing one, and away from pivot 9 l.

The flexible split construction of any finger 8? enables it to be slid longitudinally into place around its pivot after retaining strip 92 has been welded to pivots 9 l, spreading to include the pivot and snapping closed when assembled position isreached. The finger may be removed by pulling it longitudinally in the opposite direction.

Functionally, the forward part of any finger 8'1, extending from the pivot location to the.

closed end of the finger structure, may conveniently be termed the pointer portion, while the remaining rear part, comprising drive arms 93, may be termed the drive portion, as the noted parts are respectively termed in certain of the claims. 7

I claim:

1. In combination, contact members comprising separately actuatable stackups mounted side by side in a row, an actuating member underlying the stackups and means for moving it toward and away from them between a released position and an actuated position, pivots disposed along the actuating member in association with the stackups respectively and having their axes generally parallel to the path of said movement of the actuating member, select fingers supported on said actuating member for rotation about said pivots respectively, each said finger comprising a single hairpin-like member of generally uniform cross section, portions of the shanks of any finger remotely located from the closed end thereof being formed to complement each other in retaining the finger on its said pivot for rotation back and forth about it laterally of its associated stackup between an ineffective position and an effective position, movement of the actuating member into its said actuated position leaving unactuated the stackup associated with any finger which is currently in its said ineffective position, a portion at the closed end of any finger in its said effective position engaging its associated stackup to transmit the last said movement of the c uat member thereto to actuate it.

2. In combination, contact members comprising a pair of separately actuatable stackups mounted side by side, an actuatin member underlying the stackups and means for moving it toward and away from them between a released position and an actuated position, a pivot carried on the actuating member with its axis erally parallel to the path of said movement of the actuating member, a select finger supported on said actuating member for rotation about said pivot, said finger comprising a single hairpin-like member of generally uniform cross section, portions of the shanks of the finger remotely located from the closed end thereof being formed to complement each other in retaining the finger on its said pivot for rotation back and forth about it laterally of the stackups between an intermediate position and alternative effective positions corresponding respectively to said stackups, movement of the actuating mem ber into its said actuated position leaving both stackups unactuated when the select finger is currently in its said intermediate position, the shanks of the finger corresponding to the stackups respectively, a portion of the concerned shank at the closed end of the finger in either said effective position engaging its corresponding stackup to transmit the last said movement of the actuating member thereto to actuate it.

3. In combination, a contact set, a select finger having a pointer portion comprising the forward portion of the finger and having a drive portion which comprises the rear portion of the c 6 finger and consists of a pair of opposed flexible arms separated throughout such portion and joined together within the pointer portion, means pivoting the finger for rotation about the junction of said portions, a member ly ng between said arms Within the drive portion and acting therethrough to rotate the finger as a .whole to bring the pointer portion into and out of association with said contact set, and means for actuating the contact set subject to said pointer portion being currently associated therewith.

4. In combination, a contact set, a select finger having a pointer portion comprising the forward portion of the finger and having a drive portion which comprises the rear portion of the finger and consists of a pair of opposed flexible arms separated throughout such portion and joined together within the pointer portion, a pivot, said arms having mutually complementary pivot-engaging sections formed therein at the junction of said portions to retain the finger on the pivot for rotation thereabout, a member lying between said arms within the drive portion and acting therethrough to rotate the finger as a whole to bring the pointer portion into and out of association with said contact set, and means for actuating the contact set subject to said pointer portion being currently associated therewith.

5. In combination, two stackups of contact members, a finger pivotally mounted at the rear end thereof for rotation back and forth to bring the forward end into and out of association with said stackups alternatively, said finger having opposed arms of flexible material fixed therewith and extending rearwardly therefrom, a member lying between said arms to the rear of the said pivotally mounted end of the finger and acting through said arms to effect the said rotation of the entire finger, and means for actuating either stackup subject to the forward end 0i.:tt1111e finger being currently in association therew1 6. In a switch having rotatable selecting fingers and having stackups of contact members and means for selecting them respectively by rotating said fingers, opposed plate-like members spaced apart to receive the fingers therebetween, and pivots extending between said plates and arranged in a row, said fingers lying between said plates and rotatably engaging said pivots respectively, each finger being of split fiexible construction enabling it to be moved longitudinally into and out of assembled position.

JOHN I. BELLAMY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 895,842 Chambers Aug. 11, 1908 1,368,646 Morrow Feb. 15, 1921 2,120,413 Mathies June 14, 1938 2,166,764 Mathies July 18, 1939 FOREIGN PATENTS Number Country Date 49,816 Sweden Aug. 10, 1921 

